Pierre Dorion commented earlier this week that he was looking to sign a defenceman to a professional tryout contract, which is exactly what he did today, as the Senators announced the signing of Matt Bartkowski to a PTO. Bartkowski is a 28-year old left-handed defenceman who put up 18 points for the Canucks last season.
While Bartkowski is known as a fast skater and his stats look fine at first glance, he has a reputation for a lack of defensive awareness and last year was a huge drag on his defensive partners. That story from Canucks Army is well worth a read if you have time, but the basic summary is that Bartkowski's teammates were generally much better without him than they were with him. Given the Canucks suffered from the same defensive woes as the Senators last season (the Sens let in 241 goals, the Canucks let in 239), it's concerning that he couldn't even keep pace with the defenders on that team.
That being said, this is a low-risk signing by the Senators at this point -- if they think Bartkowski is one of the top six or seven defensemen on the team in early October, they can sign him to a cheap one-year deal. If they decide that they have better options in-house (or elsewhere), they can let him go.